Particularly, in connection with jumbo commercial aircraft there is a need for storing supply containers such as food containers, referred to herein as receptacles, not only on the cabin deck, but also on the loading deck in the freight space below the cabin deck. It is preferred to store as many supply receptacles, particularly food receptacles on the lower deck in order to gain passenger space on the cabin deck. The basic conventional solution to the foregoing preference is to store food, beverages, and goods for sale to passengers in special receptacles which in turn are stored in lower deck freight containers having standard dimensions or standard cross-sectional dimensions, for example size LD6. The receptacles are then lifted out of the container by a vertical lift to an on board galley location on the cabin floor. The receptacles which are initially stored in the freight container are, for example lightweight boxes or wheel equipped trolleys for transporting food along the alleys of the passenger cabin. Transport cages holding several food receptacles may also be stored in the freight containers.
When loading an aircraft, the food and supply container in the form of a special freight container can be handled just as any other freight container and is thus moved into the freight space through an under-deck freight door. However, attention is paid to place the food holding freight container into a position below a galley. Thus, in front of or behind the food holding freight container other freight containers may be positioned on the freight deck. This is possible because during the loading the cross-sectional area of the freight space is not impaired by the food or supplies holding freight container as long as the latter is handled in its proper sequence for vertical alignment with a galley on the cabin deck. This proper sequence allows to provide the aircraft with but one freight door for each freight space. Further, vertical lifts must be so positioned on the cabin deck, that these lifts do not interfere with the horizontal loading motions on the freight space.
Germany Patent Publication DE 199 55 801 A1 shows, for example, a vertical transport lift equipped with a vertical mast and a transport basket movable up and down the mast. In one conventional lift construction a support plane is positioned below the lower mast mounting so that the transport basket can be lowered onto the support plane. For this lifting and lowering of the transport basket so-called lazy tongue lifts are used, functioning as a second conveying system independently of the lift operating along the mast. The lazy tongues grip the sides of the transport basket, whereby the scissors-type motion of the lazy tongues simultaneously lifts and guides the basket. This type of transport mechanism makes it possible to load and unload supply goods through a flap of the aircraft by vertical up and vertical down movements respectively. Such a conventional additional lazy-type transport mechanism however, does not have any transport safety features which, for example are absolutely necessary when the lazy tongues are to be operated during flight. Details of the function of such a lazy tongue gripper device are not described in any detail in the above German patent publication.